1. Field of the Invention
The present invention relates to a spring plate structure for use in a motherboard to support an EMI protective shield and, more particularly, to such a spring plate structure that has a dead angle design that prevents permanent deformation.
2. Description of the Related Art
In a computer, an electrically conducting sponge may be used with a shield to protect the CPU, data storage devices and other electronic component parts of the motherboard against electromagnetic interference. Due to high manufacturing cost and labor-consuming installation procedure, it is not economic to secure an EMI (electromagnetic interference) protective shield to a motherboard with an electrically conducting sponge. Nowadays, spring plates are commonly used for securing an EMI protective shield to a motherboard. FIGS. 1xcx9c5 show a spring plate structure according to the prior art for this purpose. As illustrated, the spring plate structure 60 comprises a top contact wall 61, a bottom bonding wall 63, an intermediate connecting wall 62 obliquely connected between one end the top contact wall 61 and the bottom bonding wall 63, a first chamfer angle R1 connected between the top contact wall 61 and the intermediate connecting wall 62, a second chamfer angle R2 connected between the intermediate connecting wall 62 and the bottom bonding wall 63, an opening 64 formed in the first chamfer angle R1, and a vertical stop wall 65 extended from one lateral side of the top contact wall 61 at right angles and stopped against the top surface of the intermediate connecting wall 62. The spring plate structure 60 has the advantages of high toughness, high electric conductivity, low impedance, and rustless. However, because the left and right sides of the spring plate structure 60 are open sides, the spring plate structure 60 may hook an external body accidentally when the spring plate 60 is connected with the motherboard 80 by tin paste. Further, when received much downward pressure, the spring plate structure 60 tend to be broken, or permanently deformed.
The present invention has been accomplished to provide a improved spring plate structure, which eliminates the aforesaid drawbacks. It is the main object of the present invention to provide a improved spring plate structure, which does not hook external bodies during loading of the motherboard in which it is installed. It is another object of the present invention to provide a improved spring plate structure, which has a dead angle design that prevents permanent deformation. It is still another object of the present invention to provide a improved spring plate structure, which supports the EMI protective shield stably in position when installed, preventing a contact error.
To achieve these and other objects of the present invention, the spring plate structure comprises a bottom bonding wall, the bottom bonding wall having a first side and a second side; a first sidewall obliquely upwardly extended from the first side of the bottom bonding wall, the first sidewall having a bottom side connected to the first side of the bottom bonding wall and a top side; a top contact wall suspended above and arranged in parallel to the bottom bonding wall, the top contact wall having a first side connected to the top side of the first sidewall and a second side, the area of the top contact wall being smaller than the bottom bonding wall; a second sidewall obliquely downwardly extended from the second side of the top contact wall, the second sidewall having a top side connected to the second side of the top contact wall, a bottom side, and a longitudinal sliding slot spaced between the top side and bottom side of the second sidewall on the middle; and a first endpiece upwardly extended from the second side of the bottom bonding wall below the elevation of the second sidewall, the first endpiece having a fixed end connected to the second side of the bottom bonding wall and a free end terminating in a hooked portion hooked in the longitudinal sliding slot of the second sidewall for enabling the second sidewall to be moved vertically relative to the bottom bonding wall within a distance.